2023 Fiscal Year Final Research Report

High-Functioning Avian Cardiomyocytes Using Strategies Different from Mammals: Toward Proposing Innovative Heart Failure Treatments

Research Project

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Project/Area Number	19K22962
Research Category	Grant-in-Aid for Challenging Research (Exploratory)
Allocation Type	Multi-year Fund
Review Section	Medium-sized Section 90:Biomedical engineering and related fields
Research Institution	Nagoya Institute of Technology
Principal Investigator	Ujihara Yoshihiro 名古屋工業大学, 工学(系)研究科(研究院), 准教授 (80610021)
Co-Investigator(Kenkyū-buntansha)	毛利聡川崎医科大学, 医学部, 教授 (00294413) 中村匡徳名古屋工業大学, 工学(系)研究科(研究院), 教授 (20448046) 西辻光希福井県立大学, 海洋生物資源学部, 准教授 (60770823) 花島章川崎医科大学, 医学部, 講師 (70572981) 橋本謙川崎医科大学, 医学部, 准教授 (80341080)
Project Period (FY)	2019-06-28 – 2024-03-31
Keywords	鳥類 / ウズラ / 心筋細胞 / カルシウム / 筋小胞体 / T管膜
Outline of Final Research Achievements	The contraction and relaxation of cardiomyocytes are regulated by intracellular Ca2+ concentration. In mammalian cardiomyocytes, a special membrane structure known as the T-tubule exists, enabling rapid changes in Ca2+ concentration. On the other hand, birds lack T-tubules; however, they maintain high heart rates, suggesting that birds achieve rapid changes in Ca2+ concentration through mechanisms different from those of mammals. In this study, we compared the changes in Ca2+ concentration in cardiomyocytes between birds (quails) and mammals (rats). The results revealed that quail cardiomyocytes have a higher Ca2+ removal capacity than rat cardiomyocytes. Specifically, they achieved efficient Ca2+ concentration changes by enhancing the Ca2+ uptake ability into the sarcoplasmic reticulum, the intracellular Ca2+ store.
Free Research Field	比較バイオメカニクス
Academic Significance and Societal Importance of the Research Achievements	哺乳類の心筋細胞に存在するT管膜は，心筋細胞の収縮・弛緩を制御するCa2+の濃度変化を迅速化し，心臓の高い心拍数を支えています．そのため，T管膜の崩壊は心不全を引き起こします．しかし，鳥類の心筋細胞はT管膜が存在しないにも関わらず，高い心拍数を誇ります．本研究では，鳥類のウズラと哺乳類のラットの心筋細胞のCa2+濃度変化を比較したところ，ウズラの心筋細胞はT管膜がない代わりに，細胞内のCa2+ストアへのCa2+の取り込み能力が非常に高く，結果としてCa2+濃度変化が迅速であることがわかりました．この成果は，T管膜が崩壊した重篤な心不全に対する新たな治療法の開発に繋がる可能性があります．